Together with the developments of bio-industry, various enzymes have been used as therapeutic or healing agents. However, because most of enzymes are denatured before doing useful operation due to their very short half-life, application of the enzymes has been restricted by their low stability. Recently, the establishment of transfer systems to increase the application of the enzyme has been studied. Among many enzyme transfer systems, a transfer system using biodegradable polymer as the wall material of the microcapsules has many merits in the aspect of long-term injection (Y. Okawa, M. Yamamoto, H. Okada, T. Yashiki, T. Shimamoto, Chem. Pharmac. Bull., 1988, 5, 1095; H. Okada, Y. Doken, Y. Ogawa, H. Toguchi, Pharmac. Res., 1994, 11, 1143). However, this transfer system also requires stability for a long time storage. Generally, water-oil-water multi-emulsion systems are used to make a microcapsules containing enzymes, but the enzyme activity is decreased on the interface of water-oil (P. Couvreur, M. J. Blanco-Proeto, F. Puisieux, B. Ropues, E. Fattal, Adv. Drug Del. Rev., 1997, 28, 85; H. Sah, J. Pharmac. Sci., 1999, 88, 1320). Therefore, recently a solid-oil-water emulsion system has been used because the solid-oil-water emulsion maintains enzyme activity in the solid (T. Morita, Y. Sakamura, Y. Horikiri, T. Suzuki, H. Yoshino, J. Control. Rel., 2000, 69, 435). However, these systems have problems that lots of the enzymes capsulized in the solid-oil-water emulsion becomes denatured because of heat and physical strength received during manufacturing process.
Alternatively, various active components of a cosmetic composition have excellent effects such as improving wrinkling of the skin, whitening effect, reinforcing moisturization and antioxidation, but their application has been restricted because they are easily deteriorated through contact with external stimulants such as air or moisture, for example, discoloration, change of scent or the like. Therefore, stabilization of the enzyme is actively studied.
To solve such a problem, active components have been capsulized to be blocked it from external stimulation. Polymers have been mainly employed to capsulize the active components. Methods for capsulizing the active components using polymers include interfacial polycondensation, spray dry, coacervation, solvent evaporation or the like. Using such methods, an oil-soluble component is generally collected in hydrophobic polymer and a water-soluble component is generally collected in hydrophilic polymer. To improve stability of a water-soluble component, Jeffery et al. suggested double emulsion-solvent evaporation techniques (1993). This method capsulizes a water-soluble component more stably than simple w/o emulsion-solvent evaporation techniques, but it has a low collection rate because the water-soluble component is diffused into an aqueous media. Remunan-Lopez et al. suggested a multinuclei microcapsule that capsulizes oil- and water-soluble components at the same time by using chitosan (Eur. J. Pharma. Biopharma., 1998, 45, p.49). This method uses modified w/o/w-solvent evaporation techniques, however the microcapsules can be produced only when the following preconditions are satisfied: an inside aqueous phase should be viscous, an active component to be contained should be dispersed and perfectly dissolved in a concentrated solution of chitosan, an organic phase should be polymer dilute solution, and the organic solvent and the polymer should not be activated with chitosan.
A method for simultaneously capsulizing oil- and water-soluble components in liposome (not polymer) is disclosed in Korean Patent Publication No. 1993-211990. The liposome has a merit of capsulizing an oil- and a water-soluble component at the same time, however the stability of liposome in a cosmetic formulation has not yet been verified